Security foil with shielding from electromagnetic radiation

• US 5,796,335 A
• Filed: 01/10/1997
• Issued: 08/18/1998
• Est. Priority Date: 01/11/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Sonnentag, Dieter, Droege, Hartmut, Fischer, Ludwig, Scheibel, Markus
• Primary Examiner(s): MULLEN, THOMAS J
• Application Number:
  US08/782,475
• Time in Patent Office: 585 Days
• Field of Search: 340/550, 340/825.31, 340/825.32, 380/3, 380/52, 250/515.1, 250/505.1, 109/78, 109/80, 109/85, 428/332, 428/401, 428/911, 428/916, 428/457, 427/160, 361/749-751
• US Class Current: 340/550
• CPC Class Codes: G08B 13/128 the housing being an electronic circuit unit, e.g. memory or CPU chip protecting computer components in secure or tamper resistant housings G06F21/86; protecting computer input devices, e.g. keyboards G06F21/83
• CPC Class Codes: H05K 1/0254 High voltage adaptations; Electrical insulation details; Overvoltage or electrostatic discharge protection electrostatic discharge protection for electric apparatus in general H05K9/0067, H05K9/0079; Arrangements for regulating voltages or for using plural voltages
• CPC Class Codes: H05K 5/0208 Interlock mechanisms; Means for avoiding unauthorised use or function, e.g. tamperproof

Abstract

The invention discloses a security foil which covers a security module, wherein the security foil comprises a shielding from electromagnetic radiation from inside and outside. In a preferred embodiment the security foil comprises a metal lattice with defined lattice distances. The lattice distances can be used to change characteristics of the shielding from electromagnetic radiation, in particular the relevant spectra. The invention is especially applicable in electronic payment transactions. The invention permits effective and low-cost shielding of security modules against electromagnetic radiation from inside and outside. Additional time and labor is saved because existing components can be used.

Claims

1. A security foil for electronic detection of mechanical penetration and for electromagnetic radiation shielding of a security module which is covered by said security foil, said security foil comprising:

a flexible circuit board intrusion detection screen for covering the security module;

a metal lattice of wires with defined distances between the wires of the lattice, attached to the intrusion detection screen.

2. A security foil in accordance with claim 1, wherein the intrusion detection screen has a recess to allow for access to the security module.

3. A security foil in accordance with claim 1, wherein the metal lattice further includes electrical contacts which permit secure electrical connection of the metal lattice over a wide area.

4. A security foil in accordance with claim 1, wherein the metal lattice is galvanically protected.

5. A security foil in accordance with claim 4, wherein the metal lattice is galvanically protected by tin-plating.

6. A security foil in accordance with claim 1, wherein the security foil is executed as a two-sided flexible circuit board, wherein one side is used for intrusion detection and the metal lattice is located on the other side.

7. A security foil in accordance with claim 1, wherein outer edges of the metal lattice are recessed from the outer edge of the intrusion detection screen.